This application claims priority of Taiwanese application No. 091215255, filed on Sep. 26, 2002.
1. Field of the Invention
The invention relates to a keypad illuminating system, more particularly to a keypad illuminating system for a data processing device.
2. Description of the Related Art
As data processing devices, such as notebook computers, have become more popular and more portable, users of the data processing devices now operate their devices in many different locations. However, in locations where there is insufficient background light for keyboard operation, such as in airplanes and the like, the lack of adequate lighting may affect the user""s ability to work efficiently. Therefore, it has been attempted in the art to provide improved keyboard illumination.
U.S. Pat. No. 6,040,822 disclosed an illuminated keypad system, which includes a light source within a panel for illuminating the panel, and a window for allowing a portion of the light from the light source to illuminate keypads. Since there is a relatively large angle between the light source and the keypads, it is difficult to project a sufficient amount of light onto the keypads to achieve a proper illumination effect. Furthermore, it is difficult for the user to recognize the exact position of a desired keypad due to a shadow effect resulting from the relatively large reflection angle of the light and due to a relatively large amount of light reflected from the housing and the keypads.
U.S. Pat. No. 6,161,944 disclosed a retractable illumination device to illuminate a keyboard in a dimly lit environment. The illumination device maybe located proximate to the keyboard or on a display. However, if the illumination device is located below the display, it may suffer from the aforesaid disadvantages. If the illumination device is located on the display, the light from the illumination device may interfere with the viewing of the display.
U.S. Pat. No. 6,191,939 disclosed an information handling system which utilizes a reflective material disposed on an upper section of a housing of the information handling system to redirect light emanating from the display of the information handling system onto a portion of the housing requiring illumination, such as a keyboard. However, in addition to the aforesaid disadvantages, it is difficult to recognize the keypads since the amount of the light emanating from the display depends on the information shown on the display and is accordingly unstable. Furthermore, since the amount of the light emanating from the display is relatively small, a sufficient illumination effect can not be obtained.
Since visible light is used as the light source in the prior art, the aforesaid disadvantages may result from the limitations of the quality and the location of the light source.
Therefore, it is an object of the present invention to provide a keypad illuminating system for a data processing device, which provides a sufficient illumination effect for clear recognition of keypads in an environment having a low level of ambient light.
It is another object of the present invention to provide a keyboard for a data processing device, the keyboard having keypads capable of emitting visible light.
It is yet another object of the present invention to provide a data processing device, which includes the keypad illuminating system of the present invention.
The keypad illuminating system for a data processing device according to one aspect of this invention includes a keypad, a light source adapted to be mounted on the data processing device for illuminating the keypad, and a photoluminescent substance associated with the keypad for emitting visible light in response to the light emitted from the light source.
The keyboard for a data processing device according to another aspect of this invention includes a plurality of keypads, each of which is provided with a photoluminescent substance thereon for emitting visible light in response to light emitted by a light source on the data processing device.
The data processing device according to yet another aspect of this invention includes a display unit and a body. The display unit has a light source emitting light within a predetermined range of wavelength. The body connects to the display unit, and has a keyboard. The keyboard includes a plurality of keypads, each of which is provided with a photoluminescent substance thereon for emitting visible light in response to the light emitted from the light source.